export default{
  // 为模块化打开命名空间
    namespaced: true,
    // 模块的state数据
    state:()=>({
      // 购物车的数组，用来存储购物车中每个商品的信息对象
          // 每个商品的信息对象，都包含如下 6 个属性：
          // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
      cart:JSON.parse(uni.getStorageSync('cart') || '[]')
    }),
     // 模块的 mutations 方法
     mutations:{
       addToCart(state,goods){
        const findResult= state.cart.find((x)=> x.goods_id===goods.goods_id)
        if(!findResult){
           state.cart.push(goods)
        }else{
          findResult.goods_count++
        }
        this.commit('m_cart/saveToStorage')
       },
       
       saveToStorage(state){
          uni.setStorageSync('cart',JSON.stringify(state.cart))
       },
       updateGoodsState(state,goods){
          const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
            if (findResult) {
              // 更新对应商品的勾选状态
              findResult.goods_state = goods.goods_state
              // 持久化存储到本地
              this.commit('m_cart/saveToStorage')
            }
       },
       updateGoodsCount(state, goods) {
            const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
              if(findResult) {
                 findResult.goods_count = goods.goods_count
                 this.commit('m_cart/saveToStorage')
              }
       },
       // 根据id删除
       removeGoodsById(state,goods_id){
         console.log(goods_id);
         console.log(state.cart);
         state.cart=state.cart.filter(x => x.goods_id!==goods_id)
          console.log(state.cart);
         this.commit('m_cart/saveToStorage')
       },
       updateAllGoodsState(state,newState){
         state.cart.forEach(x=>x.goods_state=newState)
           this.commit('m_cart/saveToStorage')
       },
       
     },
       // 模块的 getters 属性
       getters: {
            // 统计购物车中商品的总数量
            total(state){
              // let c=0
              // state.cart.forEach(goods=> c += goods.goods_count)
              // return c
            return state.cart.reduce((total, item) => total += item.goods_count, 0)
            },
            checkedCount(state){
              return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
            },
            checkedGoodsAmount(state){
             return state.cart.filter(x => x.goods_state)
                                .reduce((total, item) => total += item.goods_count * item.goods_price, 0)
                                .toFixed(2)
            }
            }
            }